Cooling system for rotary mechanisms



p 1963 I w. B. GIST 'ETAL 3,102,516

COOLING SYSTEM FOR ROTARY MECHANISMS Filed Nv. 14, 1960 5 Sheets-Sheet 1F G- I- 70 2 R 4 55 55 a /Z Z /a 5 r M I 8 V 75 7 44 3 /4 F I G- 2-INVENTOR.

WILLIAM B- GIST FERDINAND F. SOLLINGER ATTORN EYS Sept. 3, 1963 w. B.GIST ETAL 3,102,516

COOLING SYSTEM FOR ROTARY MECHANISMS File'd Nov. 14, 1960 5 Sheets-Sheet2 FIG- 3.

INVENTORS WILLIAM B- GIST FERDINAND P. SOLLJNGER ATTORN EYS P 3, 1963 w.B. GIST ETAL 3,102,516

COOLING SYSTEM FOR ROTARY MECHANISMS Filed Nov. 14, 1960 5 Sheets-Sheet3 FIC14- J INVENTORS WILLIAM B- GIST FERDINAND P. SOLLINGER ATTORN EYS P1963 w. B. GIST ETAL 3,102,516

7 COOLING SYSTEM FOR ROTARY MECHANISMS Filed Nov. 14, 1960 5Sheets-Sheet 4 PIC-1-6- INVENTOR. WI LLIAM B- GIST FERDI NAN D P.SOLLINGER AT TORN EYS p 3, 1963 w. B. GIST ETA]. 3,102,516

COOLING SYSTEM FOR ROTARY MECHANISMS Filed Nov. 14, 1960 5 Sheets-Sheet5 INVENTORS' WILLIAM B- GIST FERDINAND P. SOLLJNGER May n, P fiwhm; 74

ATTORN EYS ire rates ice 3,.ltl2,5l6 COOLKNG SYSTEM FQR RGTARYMECHANESMS William Bruce Gist, Lynniield, Mass., and Ferdinand P.

Sollinger, Wayne, N..l., assignors to CurtissWriglit Corporation, acorporation of Delaware Filed Nov. M, 196%, Ser, No. 69,037 9 Qlaims.(Cl. l238) The present invention relates to means for cooling rotarymechanisms, and more particularly to a fluid cooling system for theouter body of such mechanisms.

Although this invention is applicable to and useful in almost any typeof rotary mechanism which presents a cooling requirement, such ascombustion engines, fluid motors, fluid pumps, compressors, and thelike, it is particularly useful in rotating combustion engines. Tosimplify and clarify the explanation of the invention, the descriptionwhich follows will, for the most part, be restricted to the use of theinvention in a rotating combustion engine. It will be apparent from thedescription, however, that with slight modifications which would beobvious to a person skilled in the art, the invention is equallyapplicable to other types of rotary mechanisms.

The present invention is particularly useful in rotary combustionengines of the type that is described in detail in US. Patent No.2,988,065, issued lune 13, 1961, and reference may be made to thedisclosure of this patent for a detailed description of such a rotarycombustion engine.

In a rotating combustion engine of the type described above, the heatinput to the outer body resulting from the combustion gas, or workingfluid cycle is not uniform around the inner surface of the outer body.This phenomenon occurs because each of the various phases of the enginecycle always takes place adjacent to the same portion of the outer body.As a result, the portion of the engine outer body adjacent to which thecombustion phase and expansion phase take place has a much higher heatinput rate than other portions of the outer body. Similarly, in otherrotary mechanisms, because the phases of the mechanism do not shift intheir location relative to the outer body, the heat input to the outerbody resulting from the cycle of the working fluid will not be uniformaround the inner surface of the outer body. i

In accordance with the present invention, means are provided for coolinga rotating combustion engine in operation, or, more particularly, meansare provided for cooling the outer body of such an engine. In thepresent preferred embodiment of the invention, the means for cooling theouter body comprise a multiplicity of circumferential passages in theouter body near its inner surface, a suitable cooling fluid, such asoil, and appropriate means for passing and properly distributing thecooling fluid through the peripheral Wall and end Walls of the outerbody.

In view of the foregoing, it is a primary object of the presentinvention to provide a novel liquid cooling system for the outer body ofa rotary mechanism which, in spite of large variations in the heat inputto the outer body around its inner surface, will minimize temperaturevariations in the outer body around its periphery and will ensure thatthermal stresses and distortions set up in the outer body duringoperation will be kept at a relatively low level.

Another object of the instant invention is to provide a novel fluidcooling system for a rotary mechanism in whichthe relatively coolincoming coolant fluid initially flows through the regions of high heatinput to the outer body in its circulatory path through both theperipheral .wall of the outer body and the end walls of the outer bodyand in which the coolant fluid as it increases in temperature flowsthrough regions of relatively lower heat input until it flows throughthe regions of lowest heat input just prior to leaving the outer body.

Another object of the present invention is to provide a novel fluidcooling system for the outer body of a rotary mechanism which affordsadequate cooling of the outer body with a minimum quantity of fluidcoolant and yetutilizes coolant passages having a sufficiently largeflow area for ease of fabrication and for minimizing clogging of thepassages.

Another object of the instant invention is to provide a cooling systemfor the outer body which uses coolant flow passages having smoothhydrodynamic contours, i.e., having no abrupt changes in direction orarea, particularly in regions of high heat input. This latter provisionserves to avoid the presence of dead spots in the coolant flow passages,i.e. spots in the coolant flow passages which have little or no flowvelocity of the coolant. When dead spots are eliminated in this manner,any vapor produced in the passages is instantly carried away by thecoolant flow and hot spots resulting from vapor accumulation areavoided.

Another object of the present invention is to provide a novel coolingsystem for the outer body of rotary mechanism which gives adequatecooling capacity with a minimum length cooling circuit. This shortcooling circuit is particularly adapted to the use of a combined coolantand lubricant fluid, such as synthetic oil, since the short coolingcircuit helps to minimize pressure losses in the flow path and promotesa high velocity flow which permits consequent reduction in the amount offluid required to yield a specific cooling efficiency. The coolant flowis subdivided in its downstream portion to achieve the advantages of ashort cooling circuit without sacrificing the advantages of a completeand continuous flow path for coolant in both the peripheral Walls andthe end walls.

Another object of the present invention is to provide a novel coolingsystem for the outer body of a rotary mechanism which includes means forplacing the coolant fluid in close proximity to the surface of the outerbody into whichthe principal amount of heat is being rejected.

Another object of the present invention is to provide a novel coolingsystem for the outer body of a rotary mechanism in which the coolantfluid is first circulated through the high heat rejection portion of theperipheral Wall of the outer body and then its major portion is dividedand directed into each end wall where it is principally routed to thehigh heat input areas of the end walls.

It is another object of the instant invention to provide a novel coolingsystem for the outer body of a rotary mechanism which uses for a coolantthe same type of fluid which is used to lubricate the mechanism.

Another object of the present invention is to provide a novel coolingsystem for the outer body of a rotary mechanism which includes a largenumber of finned coolant passages within both the peripheral wall andend walls of the outer body and yet is relatively inexpensive and easyto fabricate through manufacturing processes such as machining, castinand the like.

A further object of the present invention is to provide a novel coolingsystem for the outer body of a rotary mechanism which uses for thecoolant fluid the same fluid which is used to lubricate and cool thebearings and rotor of the rotary mechanism; the achievement of thisobject permits the realization of the following beneficial andadvantageous results:

(1) The conventional wate -glycol pump, tank, and lines which are neededin the usual outer body cooling system may be eliminated.

It a

(2) Servicing of the outer body cooling system is simplified, since theproblem of filling the coolant reservoir or radiator with exactproportions. of water and glycol is eliminated.

'(3) The fluid which can be used for both cooling and lubricating islighter in weight than the glycobwater mixture it replaces.

(4) The probability of leakage in the outer body cooling system isconsiderably reduced because fewer lines and fittings are needed.

The mean coolant temperature in the outer body cooling system can beraised, which permits consequent weight reduction in the cooling systemas a whole.

A still further object of the present invention, attainable because ofthe weight reduction benefits and advantages just recited, is to providea novel outer body cooling system which is particularly useful in allapplications of the rotary mechanism in which reduction of weight onlightweight construction is a desideratum.

To achieve the foregoing objects, and in accordance with its purpose,the present invention provides means which as embodied and broadlydescribed, comprises fluid coolant passages within both the peripheralwall and the end walls of the outer body of a rotary mechanism, thepassages being located close to the hottest metal portions of theperipheral wall and end walls. A suitable coolant fluid, such as oil, isfed into the inlet of the cooling systern in the peripheral wall and isforced to circulate through the hottest portions of the peripheral wall;a major portion of the coolant fluid is then divided and circulatedthrough the end walls in appropriate passages, and, finally, all thecoolant fluid is fed into an outlet manifold within the peripheral wmland from there is discharged through an outlet.

Since the present invention is particularly useful in the rotatingcombustion type of rotary mechanism, it will be described with referenceto its use in such a rotating combustion engine.

Additional objects and advantages of the invention will be set forth inpart in. the description which follows and in part will be obvious fromthe description, or may be learned by practice of the invention, theobjects and advantages being realized and attained by means of theinstrumentalit-ies and combinations particularly pointed out in theappended claims.

The invention consists in the novel parts, constructions, arrangements,combinations, and improvements shown and described.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one embodiment of the inventionand, together with the description serve to explain the principles ofthe invention.

Of the drawings:

FIG. 1 is a sectional view of the mechanism taken along the line 1--1 ofFIG. 2 and showing the rotor positioned within the outer body;

FIG. 2 is a central vertical section of the mechanism taken along theline 2-2 of FIG. 1;

FIG. 3 is a diagrammatic view and polar-type graph showing the relativerates of heat input to the peripheral wall of the outer body at allpoints about the periphery of the inner surface of the peripheral wall;

FIG. 4 is an exploded schematic perspective view of the two end wallsand the peripheral wall of the outer body of the rotary mechanism; thisview schematically shows the flow path of the coolant fluid through theperipheral wall and end walls of the outer body;

7 FIG. 5 is a plan view partly in section of the outer portion of an endwall of the outer body;

FIG. 6 is a plan View of the inner portion of an end wall of the outerbody which shows the finned passages for coolant fluid in the end wall;and

FIG. 7 is an exploded 30 isometric View showing the outer and innerportions of .the peripheral wall of the outer body and the outer andinner portions of an end wall of the outer body in their properrelationship to one another but displaced for clarity.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory but arenot restrictive of the invention. Reference will now be made in detailto the present preferred embodiment of the invention, an example ofwhich is illustrated in the accompanying drawrugs.

In the rota-ting combustion engine the enclosed combastion gasestransmit heat very rapidly to the surrounding metal Walls of the outerbody. Unless this heat is removed by an appropriate cooling system, themetal temperature will rapidly increase until the metal loses itsstrength or melts.

Even when the heat is being removed as fast as it is being put into themetal, it is a well known fact that there must be a temperature gradientin the metal in the direction in which the heat is flowing. Thisgradient has the value:

ee dz A Where o is the temperature drop per unit thickness of themetal,

is the rate at which the heat is being transferred per unit areaperpendicular to the heat flow, and k is the thermal conductivity of themetal. It can thus be seen that a high heat flow per unit area, or a lowthermal conductivity, or both of these factors combined will result in alarger temperature drop in the metal if the metal thickness is large.

The cooling system of the present invention is designed to minimize thedifference between the cool-ant temperature and the hottest metaltemperature by minimizing the metal thickness between the hot workinggases and the coolant.

This desideratum is achieved by placing substantially parallel groovesor cooling passages near the heated surface of the metal. The groovesconduct coolant circumfcrentially around the peripheral wall of theouter body from the point where the heating begins to be significant tothe point where the heat load is negligible, i.e., near the exhaust portof the engine.

At the exhaust port, the flow of coolant divides, a small portioncontinues circumferentially around the peripheral wall of the outer bodyto an outlet manifold near the point where the coolant was firstadmitted to the peripheral wall; this continuous flow around theperipheral wall promotes uniform temperature distribution within thispart of the engine. The remaining coolant subdivides into twosubstantially equal parts, the two parts being directed one to each endwall of the outer body.

Within each end wall the coolant flow again divides;

the larger portion flows through finned passages in the most severelyheated portion of the end wall, and the remainder, or minor portion,passes around the end Wall in the opposite direction, to promote moreuniform temperature distribution within the end walls. Each of thoseportions of coolant flow within each end wall is collected in separatemanifolds at a point near the outlet manifold of the peripheral wall.Each of the end wall coolant flows then joins the residual coolant flowwhich continued around the peripheral wall and the entire coolant flowleaves the peripheral wall through a single outlet.

Control of the flow distribution within the peripheral wall of the outerbody is effected by providing a suitably restricted flow passage at thepoint in the peripheral wall where the residual coolant flow enters theoutlet manifold and within each of the end walls at the point where thesmaller portion of the end wall coolant flow is collected in the endwall outlet manifold before admission into the outlet manifold of theperipheral wall.

The actual size and shape of the coolant passages must be designed foreach application of the engine; among the factors which must beconsidered are the type, quantity, initial temperature, and pumpingpressure of the coolant fluid; the thermal conductivity and temperatureresistance of the metal; and the rate of heating. In general, however,the coolant passages should be as close as is practicable to the heatedsurface of the metal, and the shape of the metal defining the sides ofthe coolant passages should have high iin effectiveness. To achieve highfin effectiveness, the coolant passages must usually be deeper that theyare wide and narrower at the bottom, i.e., toward the heat source, thanat the top.

In accordance with the invention, a rotating combustion engine and anovel cooling system for the peripheral wall and end walls of its outerbody are provided. As embodied, and as shown in FIGS. 1 and 2, thepresent preferred embodiment includes a rotating combustion enginecomprising a generally triangular rotor to having arcuate sides which iseccentrically supported for rotation within an outer body 12.

Although in the illustrative embodiment shown in the drawings the outerbody 12 is fixed or stationary, a practical and useful form of theinvention may be constructed in which both the outer body and rotor arerotary, but the eccentric is stationary; in this latter form of theinvention, the power shaft is driven directly by rotation of the outerbody and the inner body or rotor rotates relative to the outer body.

As shown in FIGS. 1 and 2 and as here preferably em bodied, the rotor 1drotates on an axis 14- Which is eccentric from and parallel to the axis1d of the ctuved inner surface of the router body 12. The distancebetween the axes l4 and 16 is equal to the effective eccentricity of theengine and is designated in the drawings. The curved inner surface 18 ofthe outer body 12. has basically the form of an epitrochoid in geometricshape and includes two arched lobe-defining portions or lobes.

As embodied, the generally triangular shape of the rotor litcorrespondsin its configuration to the inner envelope or the maximum profile of therotor which will permit interference-free rotation of the rotor illwithin the outer body 12.

In the form of the invention illustrated, the outer body 12 comprises aperipheral wall 20 which has for its inner surface a curved innersurface 18, preferably in the form of an epitrochoid and a pair ofanally-spaced end walls 22 and 24 which are disposed on opposite sidesof the peripheral wall 25 The end walls 22 and 2d support a shaft 25,the geometric center of which is coincident with the axis to of theouter body 12. This shaft 26 is supported for rotation by the end walls22 and 24 on large and ample bearings 28. A shaft eccentric 3b isrigidly attached to or forms an integral part of the shaft 26, and therotor is supported for rotation or rotatively mounted upon the shafteccentric 34 by a rotor bearing 32 which is fixed to the rotor.

As shown in FIGS. 1 and 2, an internally-toothed or ring gear 34 isrigidly attached to one end face of the rotor 10. The ring gear 34 is inmesh with an externallytoothed gear or pinion 36 which is rigidlyattached to the stationary end Wall 22 of the outer body 12.

From this construction, it may be observed that the gearing 34- and 36does not drive or imp-art torque to the shaft 26 but merely serves toindex or register the position of the rotor 10 with respect to the outerbody 12 as the rotor rotates relative to the outer body and removes thepositioning load which would otherwise be placed upon the apex portionsof the rotor llll.

As shown most clearly in FIG. 1, the rotor it} includes three apexportions 38 which carry radially movable sealing members 46. The sealingmembers ll are in substantially continuous gas-sealing engagement withthe inner surface 18 of the outer body l2 as the rotor 10' rotatesWithin and relative to the outer body 12.

By means of the rotation of the rotor lltl relative to the outer body12, three variable volume working chambers 42 are formed between theperipheral working faces 44 of the rotor it and the inner surface 18 ofthe outer body l2. As embodied in FIG. 1, the rotation of the rotorrelative to the outer body is counterclockwise and is so indicated by anarrow.

The spark plug 46, as schematically indicated in FIG. 1, is mounted inthe peripheral wall 24 of theouter body 12, and at the appropriate timein the engine cycle, the spark plug 46 provides ignition for acom-pressed combustible mixture which, on expansion, drives the rotor inthe direction of the arrow.

Also as shown in FIG. 1, one lobe of the epitrochoidal surface 18 isprovided with an intake port or passage 48,

and the other lobe is provided with an exhaust port or passage 50. Asthe rotor ll) rotates, a fresh charge is drawn into the working chambers42 through the intake passage 4%. This charge is then successivelycompressed, ignited, expanded, and finally exhausted through the exhaustpassage 5d.

All four successive phases of the engine cycle; intake, compression,expansion, and exhaust, take place Within each one of the variablevolume working chambers 42 each time the rotor 10 completes onerevolution the outer body, and for each revolution of the rotor, theengine completes a cycle.

The working faces 44- of the rotor 113 are provided with cut-outportions or channels 52 which permit combustion gases to pass freelyfrom one lobe of the epitrochoidal inner surface 18 to the other lober,when the rotor is at m near the top dead center compression position.Also, the compression ratio of the engine may be controlled by adjustingthe volume of the channels 52.

Since the gear ratio between the rotor ring gear 34 and the outer bodygear or pinion 36 is 3:2, each time the rotor 10 completes onerevolution around its own axis 14, the shaft 26 rotates three timesabout its axis 16.

As the engine operates, the various phases of the cycle of the engineworking fluid in the working chambers 42 take place adjacent to the sameportion of the outer body 12. Thus, for each working chamber 42combustion is initiated by the spark plug as, which is located adjacentto the lobe junction 47 of the peripheral Wall 20 of the outer body.

With the rotor 10 inthe position of FIG. 1, the lower working chamber $2is approximately in a position for initiation of combustion in thischamber, and combustion preferably would be initiated just prior to thechamber 42 having reached this position. Similarly to the spark plug 46,the engine intake port 48 and exhaust port 5:) successively seiveeach ofthe working chambers 42, and these ports are on the side of the outerbody opposite to the spark plug 4-6. It is apparent, therefore, that asthe engine operates, the rate of heat input or rejection to the outerbody 12, resulting from the cycle of the gas (working fluid) in theworking chambers 42, is not uniform about the outer body and is greateston the side of the outer body adjacent to the spark plug 46 wherecombustion is initiated. The actual distribution of the heat input tothe outer body peripheral wall 20 is shown by the polar-type curve 31 ofFIG. 3, and the magnitude of the rate of heat input per unit area ateach point of the inner surface 18 of the peripheral wall 20 isproportional to the radial distance between that point and the curve 31.

As is apparent from the curve 31 of FIG. 3, the rate of heat input perunit surface area to the outer body peripheral Wall 26 suddenly beginsto increase adjacent to a point 33 on the inner surface 18 of theperipheral wall 20. As is evident from a comparison of FIGS. 1 and 3,this point 33 corresponds approximately to the position of the trailingend of a combustion chamber 42 (clockwise end of the lower combustionchamber in FIG. 1) as combustion is initiated in the chamber. From thepoint 33, the heat input to the outer body increases in a counterclockwise direction about the axis 16 of the outer body approximately toa point 35 on the inner surface 18 and then proceeds to fall off so thatat the exhaust port 50 the rate of heat input per unit surface area intothe outer body peripheral wall 20 is already quite small. From theintake port 48 counter clockwise to the point 33 the heat input to theouter body is a minimum and is negligible.

It should be emphasized that the curve 31 represents the heat input tothe outer body peripheral wall 20 per unit surface area of the wallexposed to the working and this area is uniform around the peripheralwall except in the vicinity of the intake passage 48 and the exhaustpassage 50. In the vicinity of the exhaust passage 50 the total surfacearea of the outer body peripheral wall 20 exposed to the combustiongases is suddenly increased by virtue of the surface area of the exhaustpassage 50 itself. The total heat input rate to the outer bodyperipheral wall 20 in the vicinity of the exhaust passage 50 thus ismuch greater than the total beat input rate on either side of theexhaust passage although the heat input per unit surface area (curve 31)remains about the same. It is, therefore, apparent that the coolingrequirements of the outer body 12 vary considerably about its periphery.

Since almost no heat rejection takes place in the portion of the outerbody which is adjacent to the location where the intake phase occurs, itis desirable to transfer some of the heat from the hotter portions ofthe engine into the relatively cool portion which exists adjacent to thelocation where the intake phase takes place to minimize thermaldistortions within the outer body.

In accordance with the invention, means are provided to minimizetemperature variations in the outer body around its periphery and toinsure that thermal stresses and distortions set up in the outer bodyduring operation will be kept at an acceptably low level. In the presentpreferred embodiment, this means comprises a plurality of fluid coolantpassages within both the peripheral wall 20 and the end Walls 22 and 24of the outer body 12 which permit a suitable coolant fluid to circulateprogressively from the hotter portions of the peripheral Wall to thehotter portions of the end walls and, finally, into the cooler portionsof both the peripheral wall and end walls.

As embodied, the fluid coolant passages Within the outer body 12comprise a plurality of parallel passages 54 separated by walls or fins(FIG. 2 and FIG. 7) and these passagm 54 are located within theperipheral wall 20 close to the inner surface 18. Also, as embodied, thepassages 54 are formed by fabricating the outer body 12 from two parts,an outer portion 56 and an inner portion 58 (FIG. 7). When the outerbody 12 is assembled, the inner portion 53 is mated with the outerportion 56 so that the outer portion 56 covers a plurality of slotswhich have been machined or cast in the inner portion 58, and the slotswhen thus covered yield the finned passages 54 (see FIG. 2). i

As embodied, the fluid coolant passages within the end walls 22 and 24also comprise a plurality of parallel finned passages 60 within each ofthe end walls 22 and 24. Similarly to the outer body finned passages 54,the end Wall finned passages 60 are formed by the mating together oftwopar-ts from which the complete or assembled end wall is constructed.These two parts of each of the end walls 22 and 24 similarly comprise anouter end wall portion 62 and an inner end wall portion 64. A series ofslots or grooves are cut in the inner end wall portion 64, as can bestbe seen in FIG. 6, and when the outer end wall portion 62 is assembledto the inner end wall portion 64, the outer portion 62 covers the slotsor grooves to 8 form the complete end wall finned passages 60 (see FIGS.2, 5, 6 and 7).

In both the peripheral wall 2%) and the end walls 22 and 24 theperipheral wall finned passages 54 and the end wall finned passages toare preferably machined or cast and assembled in a manner which willinsure that the coolant passages have a high finned effectiveness, i.e.,the coolant passages are preferably deeper than they are wide and arenarrower at the portion toward the heat source than at the portion awayfrom the heat source.

It should be observed that the finned passages 54 in the peripheral walland the finned passages 60 in the end walls have no abrupt changes indirection or flow area. Because of this smooth hydrodynamic contour ofthe passages 54 and 6t), there are no locations in these passages whichhave little or no flow velocity of the fluid coolant and, accordingly,any vapor accumulation in these passages is instantly carried away bythe coolant flow. This smooth hydrodynamic contour of the liquid coolantpassages avoids hot spots that might otherwise be formed in the regionsof high heat input to the outer body if vapor were permitted toaccumulate at certain spots in these fluid coolant passages.

In accordance with the invention, means "are provided for insuring aneffective cooling circuit for circulation of the cooling fluid Withinthe outer body 12 which will yield a maximum cooling effectiveness for agiven quantity of cooling fluid and which will, at the same time, tendto minimize thermal distortions within the outer body by promoting moreuniform temperatures around the periphery of the outer body. Asembodied, and as can best be seen depicted schematically in FIG. 4,taken in combination with FIGS. 1 and 5, the means for insuring aneflicient cooling circuit comprise a coolant inlet passage 66 in theperipheral Wall 20 of the outer body 12. The cool-' ant inlet passage 66leads into an inlet manifold 68 which distributes the incoming coolantfluid to the peripheral wall finned passages 54.

As shown in FIGS. 1, 4 and 7, the coolant is introduced into theperipheral Wall 20 at a point which approximately corresponds to thepoint 33 on the polar-type heat rejection graph, FIG. 3, at which asubstantial quantity of heat begins to be rejected to the peripheralwall at the start of the engine combustion phase. From this point, 33,as can be seen in FIG. 4, the major portion of the fluid pursues a flowpath through the finned passages 54 around the hottest part of theperipheral wall 20 (see FIG. 3) and the major portion of the fluidcontinues this undivided flow until it reaches a point slightly past theexhaust passage 50.

A very minor portion of the fluid flows through the passages 54 in theopposite direction for a short distance around the cooler portion of theperipheral wall 20 and into the outlet manifold 72 through a smallpassage 73 which is sufficiently restricted to insure that only a veryminor portion of the fluid entering the inlet manifold 68 follows thispath. The minor flow just described, however, helps to keep thetemperature around the peripheral wall 20 as uniform as possible byremoving some of the beat being rejected to the peripheral Wall 20 inthe region of the inlet manifold 68. As shown in FIG. 2, the finnedpassages 54 are placed as close to the inner surf-ace 18 of theperipheral wall 20 as the strength of the materials will permit.

A flow distribution manifold 70 occurs in the cooling circuit in thepresent embodiment just slightly past the exhaust passage 50 within theperipheral wall 20. This flow distribution manifold 70 is shown in allfigures of the drawings except FIG. 3, but its function can best begrasped by a perusal of FIG. 4. As shown in FIG. 4, the flowdistribution manifold 70 divides the main stream of coolant fluid intothree separate portions. A residual portion continues the flow patharound the peripheral wall outlet manifold 72 from whence it iswithdrawn from the outer body by means of an outlet passage '74 in'theperipheral wall 20, and this outlet passage 74 is located adjacent tothe coolant inlet passage 66 so that the coolant fluid describes acomplete circuit around the peripheral wall.

From the flow distribution manifold 70 the remaining two portions ofcoolant flow are directed in approximately equal amounts, one portion toeach of the end walls 22 and 24. An end wall inlet manifold 76 isprovided in each end wall as a continuation of the flow distributionmanifold 70 so that the portion of coolant flow in each end wall may bedistributed to the end wall finned passages dfl. As the coolant fluidenters the end wall finned passages 60 from the inlet manifold 76, whichextends across the passages 60, it is again subdivided into two discreteflow paths. The major portion of the fluid describes a flow path throughthe finned passages 60 which is opposite to the hottest portions of theengine as shown in the polar-type graph FIG. 3, while a lesser portionof the fluid pursues a shorter path in the opposite direction which isadjacent to the cooler portions of theengine, as shown in FIG. 3. Theflow paths described by the coolant fluid within the end walls 22 and24' are clearly depicted in FIG. 4.

In accordance with the invention, means are provided for insuringdesired proportional divisions of coolant flow, first, between theresidual portion in the peripheral wall 20 and the two portions going tothe end walls 22 and 24 and second, within each end wall itself toinsure proper proportional division between the major and minor flowpaths within the end walls.

As embodied, the means for insuring the proportional division of flowbetween the residual portion remaining in the peripheral wall 20 and thetwo portions going to the end walls 22 and 24 comprises a restrictedpassage 78 on the upstream side of the outlet manifold 72 in theperipheral wall 24). This restricted passage is diensioned to give thedesired distribution of coolant flow between the portion going to theend walls-from the manifold 70 and the residual portion remaining withinthe peripheral wall 20.

Similarly, an end wall restricted passage 80 is placed within each ofthe end walls 22 and 24 at a point just downstream from a first end wallmanifold 82 which acts as a collecting point for the minor portion ofthe coolant fluid flowing in the end wall (see FIG. 5). A second endwall manifold 84- is provided adjacent to the first end wall manifold 82and serves as a collecting point for the major portion of the coolingfluid flowing through the end walls. The two manifolds, 82 and 84, meetat a common outlet portion F6 which receives the coolant fluid from boththe manifolds 82 and 84 and directs it into the peripheral wall outletmanifold 72.

From the foregoing and from a perusal of FIG. 4, it can be seen that theperipheral wall outlet manifold 72 acts as a collecting point for all ofthe coolant fluid which flows through both the peripheral wall Ztl andthe end walls 22 and 24, and the peripheral wall outlet manifold 72 isprovided with the previously described outlet passage 74 from which thecoolant fluid leaves the outer body 12.

As illustrated in FIG. 7, the fins of the finned passages 54% are cutback adjacent to the interior bosses 49 and 51 of the intake and exhaustpassages 48 and 5d. The interior bosses 49 and 51 as shown in FIG. 7,are located on the inner portion of the peripheral wall or liner portion58. The cutting back of the fins of the finned passages 54 forms anannulus to permit the fluid to flow around each of the bosses 49 and 51.When the liner or inner portion 58 is assembled to the outer portion ofthe perihperal wall 56, a complete annulus 53 is formed which surroundsthe intake passage 48 and a similar annulus is formed which surroundsthe exhaust passage 54 as close to the working surfaces of thesepassages as is structurally possible. The annulus 55 surrounding theexhaust passage 50 serves to help cool the exhaust I coolant inletpassage 66.

passage, but the coolant flowing within the annulus 53 surrounding theintake passage 38 serves a different purpose.

The fluid coolant surrounding the intake passage 48 is at a highertemperature than the temperature of the fuel-air charge which enters theengine through the inlet passage. The heated coolant fluid, therefore,serves to heat the incoming charge, and in the case of a fuel-aircharge, helps to vaporize the fuel in the charge.

After the coolant fluid has been discharged from the outlet passage 74-of the outer body 12, it is passed through an appropriate coolingradiator to return it to the desired inlet temperature and is thenrecirculated back to the Continuous circulation of the coolant fluidthrough the cooling circuit is insured by means of an appropriate pumpwithin the circuit.

The invention is also applicable to rotary mechanisms having a generalconfiguration different from that illustrated. For example, the profileof the inner surface of the outer body could be a three-lobed instead ofa two-lobed epitrochoicl with the innerbody having a generally square(as. illustrated in US. Patent No. 2,988,065, issued June 13, 1961)instead of the generally triangular shape illustrated. In addition, aspreviously stated, the invention is applicable to rotary mechanisms suchas fluid motors and fluid pumps.

From the foregoing description, it will be apparent that the novelcooling system for rotary mechanisms provided by the present inventionyields the following positive benefits, advantages, and unexpectedresults:

(1) The system keeps thermal stresses and distortions set up in theinner surface of the outer body during operation at a relatively lowlevel by minimizing temperature variations in the outer body around theperiphery of its inner surface.

(2) The system provides means for directing the relatively cool enteringfluid first adjacent to one end of a region of high input from which thefluid flows toward the other of the regions of high heat input andfinally into the regions of lowest or negligible heat input just beforebeing withdrawn from the outer body.

(3) The system provides coolant flow passages having smooth hydrodynamiccontours and avoids the creation of hot spots within the coolingcircuit.

(4) The system includes means for placing the coolant fluid in as closeproximity to the inner surface of the outer body as is structurallypermissible to withdraw the heat as efliciently as possible from theinner surface into which it is being rejected.

(5 The system permits the use of a coolant fluid which can also be usedto lubricate the rotary mechanism.

(6) The system provides for cooling of the outer body wiht a reducednumber of parts, a simplified design, less probability of leakage withinthe system, and very considerable weight reduction than can be achievedwith the conventional water and glycol cooling systems.

(7) The system provides for heating of the intake charge within theintake passage to improve vaporization of a fuel-air charge and topromote combustion efliciency.

(8) The system provides a short cooling circuit which minimizes pressurelosses in the flow path, promotes a high velocity of flow, and permits asmall amount of coolant fluid to provide a high degree of coolingefficiency.

(9) The system achieves the advantages of a short cooling circuitwithout sacrificing the advantages of a complete and continuous flowpath by subdividing the circuit in its downstream portion in the regionsof lower heat input to the outer body.

The invention in its broader aspects is not limited to the specificmechanisms shown and described, but also includes within the scope ofthe accompanying claims any departures made from such mechanisms whichdo not sacrifice its chief advantages.

What is claimed is:

1. A rotary mechanism employing a working fluid and comprising an outerbody having a cavity with spaced end walls and a peripheral wallinterconnecting the end Walls; an inner body mounted within the cavityfor ro-v tation with respect to the outer body to form working chambersbetween the inner body and outer body which vary in volume upon relativerotation of the inner body within the outer body so that a relativelyhigh temperature phase of the working fluid cycle always takes place inthe working chamber adjacent to a first region of the peripheral walland a relatively low temperature phase of the working fluid cycle alwaystakes place in the working chamber adjacent to a second region of theperipheral wall; the first region of the peripheral wall being a regionof relatively high heat input and the second region of the peripheralwall being a region of relatively low heat input; the outer body havinga plurality of peripheral wall passages extending substantially aroundthe peripheral wall for the flow of a coolant liquid through theperipheral wall; an inlet for supplying the coolant liquid to theperipheral wall passages adjacent to the region of relatively high heatinput; the outer body also having a plurality of end wall passagesextending around each end wall for the flow of a coolant liquid throughthe end walls of the outer body; a distribution manifold in theperipheral wall downstream from the inlet for connecting the end wallpassages to the peripheral wall passages; an outlet manifold in theperipheral wall, the end wall passages being connected to the outletmanifold; a restricted passage providing communication between thedownstream ends of the peripheral wall passages and the outlet manifold;and at least a portion of the coolant liquid flowing from the inletalong a relatively high heat input region around the peripheral wall tothe distribution manifold fnom which at least a portion of the liquid issupplied to the end walls and the remaining portion proceeds in theoriginal direction around the peripheral wall to the outlet manifold.

2. The invention as defined in claim 1, in which the end wall passagesinclude a first portion about a relatively high temperature region ofthe end wall adjacent to the relatively high heat input region of theperipheral wall; a second portion about a relatively low temperatureregion of the end wall adjacent to the relatively low heat input regionof the peripheral wall; a first end wall outlet manifold for the firstportion of the end wall passages; and a second end wall outlet manifoldfor the second portion of the end wall passages.

3. The invention as defined in claim 2, which includes means forrestricting flow through the second portion of the end Wall passages forinsuring that a major portion of the coolant liquid directed to each endwall flows through the first portion of the end wall passages.

4. The invention as defined in claim 2, in which the first and secondend wall outlet manifolds are connected to the peripheral wall outletmanifold.

5. A rotary mechanism as defined in claim 1, in which the'rotarymechanism is an internal'combustion engin having ignition means disposedin a working chamber in the region of relatively high heat input andincluding an intake passage for the delivery of a combustible charge tothe working chambers of the mechanism, the intake passage having itsdischarge portion disposed in heat exchange relation with the coolantliquid.

6. The invention as defined in claim 5, which ,also

includes an exhaust passage for the removal of burned gases from theWorking chambers of the mechanism, the exhaust passage having its innerend disposed in heat exchange relation with the coolant liquid.

7. The invention as defined in claim 5, which includes an annularpassage surrounding the periphery of the intake passage adjacent to itsdischarge end, the annular passage beingconnected to the peripheral wallpassages.

8. The invention as defined in claim 6, which includes an annularpassage surrounding the periphery of the exhaust passage at its interiorend, the annular passage being connected to the peripheral wallpassages.

9. A rotary mechanism employing a working fluid.

and comprising an outer body having a cavity with spaced end walls and aperipheral wall interconnecting the end walls; an inner body mountedwithin the cavity for rotation with respect to the outer body to formworking chambers between the inner body and outer body which vary involume upon relative rotation of the inner body with in the outer bodyso that a relatively high temperature phase of the working fluid cyclealways takes place in the working chambers adjacent to a first region ofthe peripheral wall and a relatively low temperature phase of theworking fluid cycle always takes place in the working chambers adjacentto a second region of the peri pheral wall; the first region of theperipheral wall being a region of relatively high heat input and thesecond region of the peripheral wall being a region of relatively lowheat input; the outer body having a plurality of peripheral wallpassages extending substantially around the peripheral wall for the flowof a coolant liquid through the peripheral wall; an inlet for supplyinga coolant liquid to the peripheral wall passages adjacent to one end ofthe region of relatively high heat input; the outer body also having aplurality ofend wall passages extending around each end wall for theflow of a coolant liquid through the end walls of the outer body; adistribution manifold in the peripheral wall downstream from'the inletfor connecting the end wall passages to the peripheral wall passages;the end wall passages being subdivided into a major portion and a minorportion within the end wall, the major portion being located about aregion of relative high heat input to the end wall adjacent to therelatively high heat input region of the peripheral wall.

References Cited in the file of this patent UNITED STATES PATENTS584,067 Wainwright June 8, 1897 851,962 Prossen Apr. 30, 1907 1,099,016Byram June 2, 1914 1,243,299 Jackson Oct. 16, 1917 1,452,024 CampbellApr. 17, 1923 1,536,851 Hewitt May 5, 1925 2,082,412 Morton June 1, 19372,450,150 McCulloeh et al Sept. 28, 1948 2,583,633 Cronin Jan. 29, 19522,677,944 Ruff May 11, 1954 2,755,990 Nilsson et al. July 24, 19562,799,253 Lindhagen et al July 16, 1957 2,849,988 Nilsson Sept. 2, 1958FOREIGN PATENTS 667,419 Germany Nov. 11, 1938

1. A ROTARY MECHANISM EMPLOYING A WORKING FLUID AND COMPRISING AN OUTERBODY HAVING A CAVITY WITH SPACED END WALLS AND A PERIPHERAL WALLINTERCONNECTING THE END WALLS; AN INNER BODY MOUNTED WITHIN THE CAVITYFOR ROTATION WITH RESPECT TO THE OUTER BODY TO FORM WORKING CHAMBERSBETWEEN THE INNER BODY AND OUTER BODY WHICH VARY IN VOLUME UPON RELATIVEROTATION OF THE INNER BODY WITHIN THE OUTER BODY SO THAT A RELATIVELYHIGH TEMPERATURE PHASE OF THE WORKING FLUID CYCLE ALWAYS TAKES PLACE INTHE WORKING CHAMBER ADJACENT TO A FIRST REGION OF THE PERIPHERAL WALLAND A RELATIVELY LOW TEMPERATURE PHASE OF THE WORKING FLUID CYCLE ALWAYSTAKES PLACE IN THE WORKING CHAMBER ADJACENT TO A SECOND REGION OF THEPERIPHERAL WALL; THE FIRST REGION OF THE PERIPHERAL WALL BEING A REGIONOF RELATIVELY HIGH HEAT INPUT AND THE SECOND REGION OF THE PERIPHERALWALL BEING A REGION OF RELATIVELY LOW HEAT INPUT; THE OUTER BODY HAVINGA PLURALITY OF PERIPHERAL WALL PASSAGES EXTENDING SUBSTANTIALLY AROUNDTHE PERIPHERAL WALL WALL FOR THE FLOW OF A COOLANT LIQUID THROUGH THEPERIPHERAL WALL; AN INLET FOR SUPPLYING THE COOLANT LIQUID TO THEPERIPHERAL WALL PASSAGES ADJACENT TO THE REGION OF RELATIVELY HIGH HEATINPUT; THE OUTER BODY ALSO HAVING A PLURALITY OF END WALL PASSAGESEXTENDING AROUND EACH END WALL FOR THE FLOW OF A COOLANT LIQUID THROUGHTHE END WALLS OF THE OUTER BODY; A DISTRIBUTION MANIFOLD IN THEPERIPHERAL WALL DOWNSTREAM FROM THE INLET FOR CONNECTING THE END WALLPASSAGES TO THE PERIPHERAL WALL PASSAGES; AN OUTLET MANIFOLD IN THEPERIPHERAL WALL, THE END WALL PASSAGES BEING CONNECTED TO THE OUTLETMANIFOLD; A RESTRICTED PASSAGE PROVIDING COMMUNICATION BETWEEN THEDOWNSTREAM ENDS OF THE PERIPHERAL WALL PASSAGES AND THE OUTLET MANIFOLD;AND AT LEAST A PORTION OF THE COOLANT LIQUID FLOWING FROM THE INLETALONG A RELATIVELY HIGH HEAT INPUT REGION AROUND THE PERIPHERAL WALL TOTHE DISTRIBUTION MANIFOLD FROM WHICH AT LEAST A PORTION OF THE LIQUID ISSUPPLIED TO THE END WALLS AND THE REMAINING PORTION PROCEEDS IN THEORIGINAL DIRECTION AROUND THE PERIPHERAL WALL TO THE OUTLET MANIFOLD.